gpio: bail out silently on NULL descriptors

[mirror_ubuntu-artful-kernel.git] / drivers / gpio / gpiolib.c

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 68dbff5d8f57fc05fa717aafeffc77f7567d9919..246b6b051b0d79f6f5547a8a541ba79b9f8086af 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1367,10 +1367,13 @@ done:
 /*
  * This descriptor validation needs to be inserted verbatim into each
  * function taking a descriptor, so we need to use a preprocessor
- * macro to avoid endless duplication.
+ * macro to avoid endless duplication. If the desc is NULL it is an
+ * optional GPIO and calls should just bail out.
  */
 #define VALIDATE_DESC(desc) do { \
-       if (!desc || !desc->gdev) { \
+       if (!desc) \
+               return 0; \
+       if (!desc->gdev) { \
                pr_warn("%s: invalid GPIO\n", __func__); \
                return -EINVAL; \
        } \
@@ -1381,7 +1384,9 @@ done:
        } } while (0)
 
 #define VALIDATE_DESC_VOID(desc) do { \
-       if (!desc || !desc->gdev) { \
+       if (!desc) \
+               return; \
+       if (!desc->gdev) { \
                pr_warn("%s: invalid GPIO\n", __func__); \
                return; \
        } \